Fire pan



Patented Mar. l, 1927.

'UNITED STATES 1,619,453 PATENT OFFICE ALFRED H. WILLETT, F WEST NEW YORK, NEVI JERSEY, ASSIGNOR TO AMERICAN ARCH COMPANY, A CORPBATON OF DELAW'ARE. i

FIRE PAN.'

Application filed August 6, 1921. Serial No. 490,195.

My invention relates to fire pans for furnaces fired with fuel in gaseous, vaporous, or suspended condition, and is of especial advantage for fire pans or flash pans of oil burning locomotives. The invention is particularly concerned with the supply of air for combustion to the lire pan and the furnace, my aim being to provide for heating the air and for cooling the furnace or fire pan structure, so as to improve the combustion andthe fuel economy and to preserve the furnace against too rapid deterioration under the intense heat. In the embodiment of my invention hereinafter described (the best at present known to me), both of the above-stated objects are effected; and this 1s done in such a way that the furnace structure is cooled by air that is supplied to the fire ypan to support combustion, andv is'thereby heated. f t

It is also an object of my invention to provide an improved construction for the floor of the flash pan of an oil buring locomotive wherebyit can be made of a plurality of bricks similar to those used in the arches.

Such a construction is now known in the art as sectional I, therefore, provide a sectionally constructed bottom or floor for the flash pan.

The foregoing, together' with such othertive boiler with my invention applied thereto.

Fig. 2 shows a cross sec-tion through the fire pan, taken as indicated by the line 2?, in

Fig. 3 is a fragmentary ,View similar to Fig; 2, showing-'a modified arrangement for air admission and the use ofa greater number of tubes for supporting the bricks of the floor than `is shown in the other figures.

F ig. 4:A is a fragmentary View similar to Fig. l, showing still another arrangement forair admission. v v

The .flocomotivefire box 5 shown in Fig. l is of a familiar type. It is provided with the usual sectional fire arch 6 extending rearwardand upward from the -lower portion of the tube sheet 7 and consisting of `hre brick vthe bottom of the fire box 5 is a lire pan structure 1l whose general yform and construction are also familiar in the' art. may be briefly describedas comprising a metal floor sheet or shelf l2 extending inwarchfrom the bottom of the mud ring 13, and a metal trough 'lil with sloping sides l5, extending fore and aft within and below the inneredges of the shelf 12. y'The front end 16 of the trough 11i slopesrather steeply, and has an opening l? into which :pro

jects an oil burner 18, and through which an initial supply of air for combustion is also admitted. The rear end 19 of the troughld is shown as vertical, and serves to arrester baille the jet, blast, or stream-of fuel and air from the burner V18, mix it up, and throwit foiwvard. and upward into the superjacent combustion Vchamber or furnace proper-'of the fire box 5. The fire v.pan structure ll has a refractory lire brick Ilining,shown as thick-` est at and above the rear end 19. of the trough or fire pan proper `14e. It has also a solid refractory-lined floor or shelf of narrow width at its rear end.

Prior to my invention, the practice has' been to admit a large supply of yair (additional `to that admitted at the burner 18, and usually exceeding it in amount) =`to the fire pan 14: in a large, cold blast.V The coldness of this considerable Vsupply of air affects the operation, economy,'and useful life of the furnace unfavorably, since it tends to chill the iiaming fuel stream below the combustion temperature, to chill the walls ofthe furnace and the lire pan locally as it Vstrikes vthem in one spot or another with the eddy'ing and swirling of the llames, and to produce uneven combustion. By preheating this main air supply on its wayr into -the fire pan, .I

promote thorough, uniforn'rand efficient comsubstantially horizontal fore yand aft tubes 25 that serve as air passages in the fioor. At their' forward ends, the tubes 25 extend and open out through a downward extension 26 of the front trough wall 16; while at their other ends, they open rearward into the fire pan 14 through a chamber or compartment 27 that opens -upward into said fire pan. The chamber 27 serves as a clean-out hopper for refuse, slag, etc., from the superjacent fire pan 14, and its rear wall 28 is hinged at 2S) to permit of its being swung rearward and upward for removal of` accumulated slag and ash from time to time. rlhewhole fioor 20 being heated by the burning fuel stream above it, the air entering the tubes 25 at the forward end ofthe fire pan 14 is thoroughly heated as it passes rearwardV through them; and in this preheated condition, it is discharged into the burning fuel stream above the floor and mingles and unites with it. i

In the flooring 20 supported by the tubes d25 are a number of openings 30 through which air passes directly upward to the fire pan 14, being preheated in its passage. As shown, these openings are individually rather narrow, so that the air passing through them shall be more effectually preheated by radiation and conduction from the bric-k. Air is also admitted to the compartment 27 vand the fire pan 14 beneath the floor 20, through a multitude of small openings 33 Vin the forward Wall 34 of said compartment. This air (as Well, indeed, as that admitted through the openings 30) is preheated "by coming against the fioor 20 on its way to the openings through which it enters the fire pan 14,--as also by radiation and conductionV downward from the floor. As shown, the air entering the fire pan 14 through the holes 3() and 33 is directed against the floor 20 and brought in contact with it by means of an air intake casing or chamber 35 beneath the floor, in front of the compartment 27. Air is admitted to the casing 35 through transverse openings 36 in its lower side or wall, and these openings are controlled and the passage of the air through the casing 35 regulated by adjustable dampers 37 pivotally mounted in the openings and operable in `unison by a common rod 3S pivoted to their depending actuating crank arms 39. The rod 33 may, if desired, be connected with the usual Vfiring valve (not shown) that controls and regulates the burner 18.

Not only is the combustion air supply preheated in the floor passages 25, in the floor openings 30, and in the casing 35, but the floor 20 is cooled and protectedagainst the ill effects of overheating by this same air.

In the modified arrangement illustrated in Fig. 3, the openings 46 for admitting air to the casing 35 are in its opposite sides or walls instead of in its bottom (as in Figs. 1 and 2), and the admission and passage of air through the casing is controlled by ad justable vertically swinging dampers 47 pivoted at their upper edges just above these openings. i

In this ligure there is also shown the use of a greater number of tubes 25 for support-- ing the brick 22a than is shown in the other figures, which arrangement is somewhat more substantial and secure.

In the modified arrangen'ient illustrated in Fig. 4, the openings 56 for admitting air to the casing 35 are in its forward end or wall insteadof in its bottom as in Figs. 1 and 2). and the adjustable swinging damper 57 that controls and regulates this opening also overlaps the forward ends of the tubes 25 und controls and regulates the admission 2. The combination of a fire pan vvithfore` and aft air supply tubes receiving air at the forward end thereof and discharging into the pan at their rear ends, refractory flooring supported by saidtubes, and an air intake casing beneath the floor thus formed, with means for admitting air heated in said Vcasing into the fire pan.

3. The combination of a fire pan with fore and aft air supply tubes receiving air at the forward end thereof and discharging into the pan at their rear ends, refractory flooring supported 'bv said tubes, and an air intake casing beneath the floor thus formed, with means for admitting air heatedin said casing into the fire pan, and means for regulating the passage of air through said casing.

4. The combination of a fire pan"`with fore and aft air supply tubes receiving air at the forward end thereof and discharging into the pan at their rear ends, refractory'floon ing supported by said tubes, and an air intake casing beneath the floor thus formed, with means for admitting air heated in said casing into the fire pan including a plurality of openings upward through said fioor, and `,a damper-controlled opening in the wall of said casing for admission of air thereto.

5. The combination of a fire pan with fore and aft air supply tubes extending from the forward end thereof rearward into adelivery compartment opening upward into il (l admitting air heated in said compartment to the fire pan including openings upward through said floor and openings rearward into said compartment.

6. The combination of a fire pan with air supply tubes having one end open to the .atmosphere and discharging into the lire pan at the other end and a refractory floor supported by said tubes, and means permitting an additional circulation 0f air between and around said tubes.

7. In combination with a fire pan, air supply tubes having one end open to the atmosphere and discharging into said pan at the other end, a refractory floor supported by said tubes, and an air directing casing beneath said floor.

8. In combination with a lire pan, air supply tubes having one end open to the atmosphere and discharging into said pan at the other end, a refractory floor supported by said tubes, an air-directing casing beneath said iloor, and air-inlets between said casing and said pan.

9. In combination with a fire pan, air supply tubes liaving an air-intake end and discharging into said pan at the other end, a refractory floor supported by said tubes, a easing beneath said tubes and floor7 air-inlets between the casing and said pan, an airintake at an end of the casing, and an adjustable damper at the air intake end of the tubes and casing.

10. The combination with a fire pan of a plurality 0f tubes underlying said pan, said tubes heilig open at their ends for admitting air freely into said fire pan, and externally controlled means auxiliary to said tubes for admitting an additional supply of air int-o said lire pan.

In testimony whereof7 I have hereunto signed my name.

ALFRED H. WILLET'I. 

